1. Field of the Invention
This invention relates to a universal focal plane DEWAR assembly and more particularly to a glass infrared detector DEWAR of the cryogenically cooled type, which is of three components, a front window, a glass housing and glass bore, wherein the expander and cold finger is not integral with the assembly.
2. Description of the Prior Art
Infrared detectors and sensors (IFA) integrated focal plane arrays such as used with infrared cameras require cooling, and often use expanders and cold fingers as part of their cryogenic cooling systems which are integrated into a welded enclosure which complicates servicing the system. The cryogenic cooling systems have relatively short lives, are expensive to replace, and by the nature of their construction there is a large risk of damage to the focal plane of the assembly when the cryogenic cooling system requires rework, and/or replacement.
The unavailability of reliable low-cost cryocoolers for use with electronic devices has been known in the industry, and is extensively discussed in an article in the publication Superconductor Industry, issue fall of 1992, entitled: Building The Better Cryocooler, pages 22-28. The universal focal plane DEWAR assembly of the invention is easy to assemble and disassemble, and does not suffer from the shortcomings of the previously available devices.